The present invention relates to a system and method for transferring data between apparatuses or between modules, and more particularly to a data transfer system and method for encrypting data for copyright protection and transmitting it together with use condition data and other relevant information.
In recent years, the Internet and other information communication networks and the apparatuses for using such networks have rapidly made progress. Under these circumstances, data is digitized, transmitted/received, and recorded on media. Advantageously, digital data recorded on a medium can be readily duplicated without degrading its quality. Meanwhile, the rights of copyright holders of music data, image data, and other copyrighted data can be significantly violated unless they are properly protected. However, if top priority is given to copyright protection so that digital data distribution is obstructed, the profits of copyright holders are diminished although they can collect copyright fees at the time when their copyrighted products are duplicated.
Copyrighted data is distributed mainly through a digital communication network or broadcast wave. In a majority of cases where general users use such data, they record data in a storage device, which comprises, for instance, a semiconductor memory, mount the storage device in a player, and play back the stored data. In some cases, the storage device is built in a recorder/player. For the sake of convenience, however, it is highly probable that a portable storage device will be frequently used. One example of a portable storage device having a copyright protection function is a memory card that is described in Non-Patent Document 1 (http://panasonic.jp/sd/whats_sd/index.html).
As a data player, a recorder/player for use in receiving the above distributed data or a dedicated portable player is used. To protect the rights of copyright holders in such an instance, it is necessary to incorporate a security feature in the recorder/player and storage device so that the data recorded in the storage device cannot be played back beyond the limits defined by the copyright holders. More specifically, it is necessary to perform an authentication process, encryption process, and other appropriate processes on data transfers that are made in an internally or externally accessible region of the associated apparatuses.
Proposals made in Patent Documents 1 (Pamphlet WO01/013358) and 2 (Pamphlet WO01/043339) provide copyright protection by encrypting the digital data for use, defining a key for decrypting the data, and establishing the conditions for using the decrypted data in such a manner as to avoid illegal data acquisition, data falsification, and the like.